Apparatus for sinking forms for concrete piles



April 29, 1941.

APPARATUS FOR SINKING FRMS FOR -CONCRETE PILES E. 1'. BEPLAT Filed March25, 1939 ATTORNEYS Fatented pr. 29, 1941 iJNlTED STATES PATENT OFFICEAPPARATUS FOR SINKING FORMS FOR CONCRETE PILES 6 Claims.

The present invention relates to pile driving, and more particularly toan improved apparatus for rapidly and effectively sinking tubular formssuch as are used in the construction of concrete piles, although it isnot limited to such use.

In the present method of sinking forms of this character, the form isdriven into the earth by means of a Isuitable hammer until the forces oifriction acting inside and outside the form substantially retard itsmovement. 'I'he driving lis then stopped and the material within theform is blown `out by means of air under pressure from a hose loweredinto the' form. By alternate driving and blowing in this manner, theform is iinally sunk to the desired depth.

The method described above has been found to be generally unsatisfactoryin several respects. For one thing, it cannot be used economically v indriving formsof large diameter, because the cost of providing sufficientair to maintain the necessary pressure in such forms, for the effectiveremoval of the excavated earth is excessive. Accordingly, it has beenthe customary practice to sink a plurality of forms of relatively smalldiameter rather than one or several forms of large diameter, althoughthe latter is by far the better practice.

The principal objectof the present invention, accordingly, is to providean improved apparatus for sinking forms for concrete piles, which isfree from the defects of the prior art mentioned above, and by means ofwhich forms of relatively large diameterI may be sunk economically andin a rapid and highly effective manner.

Another object of the invention is to provide an improved apparatus ofthe above character in which the earth within the boundary of the formmay be excavated simultaneously with the driving of the form.

A further object of the invention is to provide an improved apparatus ofthe above character which is adaptable for use in sinking `piles ofdiierent diameter. l

In a preferred embodiment of the invention, a blowing head is providedwhich is adapted to be lowered within a. form, and which comprises aplurality of nozzles concentrically disposed about a discharge opening.Air under pressure is adapted to be directed from the nozzles againstearth adjacent the periphery ofthe form, which is broken up andldischarged together with the air, through the discharge opening in thehead.

y The excavated material and air are then carried up the form through aconduit of relatively Vsmall diameter, in which the required pressuremay be readily maintained with ordinary and economical quantities ofair. Suitable means is provided in accordance with the invention forpreventing the escape of air between the blowing head and the inner wallof the'form.

Additional objects will become apparent from the following detaileddescription taken in connection with the accompanying drawing, in which:

Fig. 1 is a view in vertical section of the lower Portion of anexcavating device constructed in accordance with theinvention, and in anoperative position within a form;

Fig. 2 is a view in vertical section illustrating the upper portion ofthe apparatus including the driving member;

Fig. 3 is a view in section taken along line 3 3 of Fig. l, looking inthe direction of the arrows;

Fig. 4 is a view in section taken along line t-ll of Fig. 1 looking inthe direction of the arrows; and

Fig. 5 is a view, partially in section, illustrating an alternativeoperative position of the device.

Referring to Fig. 1, a tubular form section is shown at ll), within thelower portion of which a blowing head ll has been lowered'. The blowinghead il may be shaped to conform with the cross section of the form l0,and is provided with a centrally disposed discharge opening I2 throughwhich excavated earth is adapted to be discharged. Formed within thehead il is an annular passage i3 terminating at the lower extremity ofthe head il in a plurality of nozzles it of relatively small diameter,through which air under pressure is adapted to be directed against theground adjacent the periphery of the form it.

At the upper portion of discharge opening l2 a circular recess i5 isprovided, within which a discharge pipe It is adapted to be secured. Asimilar recess i5 is provided in the upper portion of the air passage i3in which a second pipe ll of larger diameter than the discharge pipe i6is adapted to be received. 'Ihe space between the discharge pipe i6 andthe outer pipe Il provides an annular conduit Il through which air underpressure may be directed to the passage i3 in the blowing head Il forbreaking up earth at the lower extremity of form section lll.

The discharge pipe IS may be welded `or otherwise secured to a secondsection of pipe I8, which in turn is Welded to the pipe I9 which directsthe excavated earth to the discharge opening at the upper end of theform. The outer pipe I1 is closed oi by a suitable closure member 20welded tov withstand high air pressure, which is provided with anaperture 2| into which an air supply pipe 22 is adapted to be fitted.The air supply pipe 22 may be held in position by means of a suitableclamp 23 bolted or otherwise secured to the pipe I9. 'Ihe length of theform may be increased by providing a suitable'coupling member 24 of awell known type, on which a second section 25 may be seated, and thelength of the air supply pipe 22 and the discharge pipe I9 may beincreased by adding sections in the conventional manner, using similarcoupling members (not shown).

At the upper end of section 25 (Fig. 2) a coupling member 26 is providedon which a driving head is adapted to be seated. The coupling memfber 25has a wide ange 21, in the under side of which a plurality of concentricgrooves 2:3 are formed to accommodate forms of diierent diameter,section 25 being in one of the grooves 28. In the upper portion ci thecoupling member 25, a circular recess 29 is formed in which the drivinghead 30 is adapted to be seated. In the upper portion of theI drivinghead 30 a circular plate 3| is secured to form a cylindrical chamber 32,within which an anvil 33 is adapted to be received. The anvil 33 may beprovided with a plurality of recesses 34 in which the legs 35 of theusual driving hammer 36 are adapted to be positioned.

In the lower portion of the driving head1 30 a circular plate 31 issecured within which the apertures 38 and 39 are formed. Fitted withinthe aperture 38 is a short section of pipe 40 into which the upperextremity of the air supply pipe 22 is adapted to be slidably received.In order to provide an air-tight joint suitable packing 4| isprovided,'which is held in place by means of glands 42 and 43, securedat the upper extremity of the pipe 22.

Fitted within the aperture 39 in plate 31 is a short section of pipe 44of relatively large diameter, which is adapted to be slidably receivedwithin the discharge pipe I9. An air-tight joint is provided by means ofthe packing 45, which is held securely in place by the glands 45 and 41,secured at the lower extremity of the pipe section 44. It will be notedfrom the above that the distance between the driving head and theblowing head II may be varied over a slight range without breaking theconnections to the air supply and the discharge pipe located at theupper portion of the forn'r 25.

A vertical member 48 is secured between the plate 3| and the plate 31which forms an airtight enclosure into which air may be introduced froman air inlet 49 fitted in the wall of the driving head'30, by means ofwhich air may be directed to the air supply pipe 22. A curved member 50is secured to the vertical member 48 for directing the excavated earthfrom the discharge pipe 44 to an aperture 5Iv formed within the drivinghead 30. It will be evident that the curved memhowever, a space existsbetween it and the form ingly means is provided for blocking'o this airspace during the blowing operations, as described below, in order thatthe air pressure within the form may be maintained as high as possible.

As shown in Fig. .1, a circular groove 52 is formed at the upper portionof the blowing head II, within which are provided a plurality of sectors53 made of resilient material-such as, for example, rubber. Three su'chsectors 53 are shown in Fig. 4, although any number might be used. Eachof the sectors 53 is provided with a centrally disposed guide hole 54within which a guide pin 55 is adapted to be received. The guide pins 55may be secured to the outer pipe I1, as shown in Fig. 4, and where threesectors 53 are used their centers are preferably placed approximately120 apart.

Above each of the pins 55 in the pipe I1 is a check valve 55 (Fig. 1)which is normally closed, but which is adapted to be opened whenever airunder pressure is present in the passage between the discharge pipe I5and the outer pipe I1. It will be evident that as soon as air underpressure is supplied to the device through thev inlet 49, the checkvalves 56 will be opened and a blast of air under pressure will bedirected against each of the sectors 53, causing them to move outradially until they are in engagement with the inner wall of the formI0. It will be noted, however, that as the sectors 53 move outwardly,they tend to separate from each other so that a space exists betweeneach of them, the centers of the spaces being approximately 120 apart,as shown in Fig. 4.

In ord-er to prevent the escape of air through these spaces, auxiliarysectors 51 (Fig. 4), also of resilient material, are provided. Each ofthese sectors 51 (Fig. 1) comprises a lower portion 53 of relativelysmall thickness, and an upper portion 59, whose width is such that itwill lie ush with the two adjacent sectors 53 when its lower portion 58is in contact with the rear sides of the adjacent sectors 53. Y

Each of the sectors 51 is also provided with an aperture 60 (Fig. l)within which a guide pin 6| is adapted to be received, the guide pinsagain being secured to the outer pipe I1 and disposed approximately 120apart. In order that the auxiliary sectors 51 may move out radially ontheir guide pins simultaneously with the sectors 53, additional checkvalves 62 are provided in the pipe I1, which are normally closed, butwhich are adapted to be opened whenever air under' pressure isintroduced into the apparatus. It will be evident that as soon as air issupplied to the apparatus, the sectors 53 and auxiliary sectors 51 willsimultaneously move outwardly and radially'on their guide pins 55 and5I, respectively, thus preventing the escape of air between the blowinghead and the form III.

As shown in Fig. 3, the upper portions of the sectors 53 are held inplace by means of suitable flange sectors 63 which may be bolted orotherwise secured to the outer pipe I1. The auxsection III through whichair escapes. Accordiliary sectors 51 are likewise held in place bysimilar flange sectors .64 also secured to the outer pipe I1, so thatthe assembly is substantially airtight.

In operation the form II'I may be driven into the earth for a shortdistance so that the blowing head I rests upon the earths surface sulstantially as shown in Fig. 1. Air under pressure is then supplied tothe inlet 49 and is directed from the nozzles I4 against the earthadjacent the lower periphery of the form III. The

charge opening I2, pipe I6, pipe I8, pipe I9, pipe 44 and out throughaperture 5I. -It will be noted that the blowing head removes the earthwithin the boundary of the periphery of the form I so that the onlyfrictional force retarding the movement of the form IIJ is that due tothe earth adjacent its outside surface. Accordingly, the power requiredto drive the form in accordance with the present invention issubstantially less than that required previously.

.Moreover, the driving head 30 may be driven during the blowingoperation, thus enabling both the blowing and driving operations to beper-V formed simultaneously. In certain cases as, for example, where thesoil is relatively soft, the weight of the head casting 30 and the anvil33 will be suiiicient to sink the form I0 without the application of anyexternal force.

The sinking operation may be further expedited by permitting the blowinghead I i to lead the form I0 by a slight distance, as shown in Fig. 5.When this is done the ground is excavated to a substantial distancebeneath the form l0, and only a relatively slight force is required tosink the form i0 to the required depth.

Before removing the blowing head l i from the form l0 after the drivingoperation has been completed, it is necessary that the sectors 53 and 51be moved back into theirv normal positions in order to enable the deviceto be moved past the coupling member 24. For this purpose a plurality ofvertical grooves 65 are formed in the surface of the sectors 53. Thesegrooves 65 communicate with the space between the blowing device and theform at one end, but since they do not extend for the entire width ofthe sectors 53, air cannot` escape from the blowing nozzles I4 betweenthe blowing head li and the form section l0. Similar grooves 66 areformed in the surface of the sectors 51 which, likewise, are blocked oiat their lower end but which communicate at theirupper ends with thespace between the blowing device and the form.

When it is desired td move the sectors 53 and 51 to the normaldisengaged position, air under pressure is introduced by means of theinlet 68 into the space between the form and the blowing device abovethe sectors 53 and 5l. This'air passes down through the grooves 85 andt6 and exerts sufElcient pressure to push the sectors 53 and 51 radiallyon their guide pins away from the inner wall of the form. Inasmuch asthe check valves 56 and 62 close when the blowing operations arediscontinued, a plurality of small vents 61 are provided in the blowinghead il through which air trapped behind the sectors 53 and 51 mayescape as the sectors 53 and 51 are moved away from the inner wall oithe form.

A plurality of blowing heads of different sizes may be provided forsinking pipes of various diameters up to the largest size desired. Inall of the blowing heads, however, the diameter of the discharge pipe i6will be maintained substantially the'same, and this diameter will besuch that the pressure required for discharging excavated earth may bereadily maintained without using excessive quantities of air. i

It will be evident from the foregoing that forms relatively large indiameter may be sunk rapidly, eii'ectively and economically inaccordance with the present invention, and, since the blowing anddriving operations maybe performed simultaneously, considerable savingin time is eiected. Moreover, the curved member 50 and the aperture 5|enable the direction of discharge of the excavated earth to becontrolled, thus preventing possible damage to the clothing of passersbyfrom contact with the material being discharged. This combination alsoeliminates the delays sometimes caused by the necessity for stopping theblowing operation in order i to let pedestrians pass without fear ofhaving their. clothing soiled.

While a preferred embodiment of the invention has been described indetail above, the invention is not intended to be in any way limitedthereby, but is susceptible of numerous changes of form and detailwithin the scope of the appended claims.

I claim:

1. In apparatus for sinking forms, the combination of a tubular memberadapted to be lowered into a form, said tubular'` member having apassage therein for directing air against earth at the bottom oftheform, and having a centrally disposed discharge opening therein, acover member on the form having an air inlet vand a discharge outlettherein, a substantially airtight, telescoping conduit connected betweensaid air passage and the air inlet, a second sub- `stantially airtight,telescoping conduit between said discharge opening and the dischargeoutlet, said conduits permitting relative movementv of said tubularmember with respect to the cover member during the sinking of the form,an anvil on the cover member, and means for striking the anvil, wh-erebyearth within the form may be removed simultaneously with the drivingthereof.

2. In apparatus for sinking forms, the combination of a tubular memberadapted 'to be lowered into a form, said member having a plurality ofnOzzles therein concentrically disposed about a centrally locateddischarge opening, means forming a passage in the tubular member fordirecting air to said nozzles, a conduit within the form for directingair under pressure to said passage in the tubular member, a secondconduit within the form for directing excavatedl earth from thedischarge opening, a plurality of resilient cylindrical sectors disposedabout said air directing conduit and a plurality of check valves in saidlast-named conduit adapted to direct air under pressure therefromagainst said sectors to move them into engagement with the form, wherebythe escape of air between said tubular member and the form may. beprevented.

3. In apparatus for sinking forms, the combination of a tubular memberadapted to be lowered into a form, said member having a plurality ofnozzles therein concentrically disposed about a centrally locatedvdischarge opening, means forming a passage in the tubular member fordirecting air to said nozzles, a conduit within the form for directingair under pressure to said passage in the tubular member, a secondconduit within the form for directing excavated earth from the dischargeopening, a plurality of movable resilient cylindrical sectors disposedabout said air directing conduit, each of said sectors having anaperture therein, a plurality of spaced guide pins on said last-namedconduit, adapted to be receivedA within said apertures, means on saidair directing conduit for limiting the extent of movement of saidsectors and forming therewith a substantially airtight assembly and aplurality of air check valves in said last-named conduit for directingair against said sectors to move them outwardly on the guide pins intoengagement with the form whereby the escape of air between the tubularAmember and the formA may be prevented. A

i 4. In apparatus for sinking forms, the combination of a tubular.member adapted to be W- ered into a form, said member having aplurality of nozzles therein concentrically disposed about a centrallylocated discharge opening,

tubular member and the air inlet, the lower portion of said secondconduit being concentric with means forming a passage in the tubularmember for directing air to said nozzles, a conduit within the form vfordirecting air under pressure to said passage in the tubular member, asecond conduit within the form for directing excavated earth from thedischarge opening, a plurality of movable resilient vcylindrical sectorsdisposed about said air directing conduit, means on said air directingconduit for limiting the extent of movement of said sectors and formingtherewith a substantially airtight assembly, a plurality of check valvesin said last named conduit for directing air therefrom against saidsectors` to move them into engagement with the form, said sectors havinga plurality of longitudinal recesses formed in the surfaces thereof,communicating at their upper. extremities with the space between theform and the tubular member,` and being less in length thanl the lengthof said sectors, an'air inlet for introducing air under pressure intothe form above the tubular member to move the sectors away from theform, and a plurality of air vents for venting air trapped behind saidsectors, whereby the sectors may be moved out of engagement with theform to facilitate the removal of the tubular member therefrom- 5. Inapparatus for sinking forms, the combination of a tubular member adaptedto be lowered into a form, said tubular member vbeing of lesser diameterthan the diameter of the form, and having a plurality of nozzles thereinconcentrically disposed about a centrally located discharge opening,means forminga passage in the tubular member for directing air to saidnozzles, a cover member on the form,- having an air Vand of greaterdiameter than said rst conduit,

a plurality of resilient sectors disposed about the lower portion ofsaid secondY conduit, each having an aperture therein, a-plurality ofguide pins on the lower portion of said second conduit, adapted to bereceived Within said apertures, means on the lower portion of saidconduit for limiting the extent of movement of said-sectors and formingtherewith a substantially airtight assembly and a plurality of air checkvalves in the lower portion of said second conduit for directing airtherefrom against said sectors for moving them outwardly into engagementwith the form, whereby the escape of air between the tubular member andthe form may be prevented.A

6. In apparatus for sinking forms which includes a hollow member adaptedto belowered into a form, said hollow member having passages therein fordirecting air againt earth at the bottom of the form, and having acentrally disposed discharge opening therein, the combination of abearing member on the form, a driving head mounted on the bearingmember, said driving head having an air inlet and a discharge outletassociated therewith, a substantially airtight, telescoping conduitconnected to said air inlet and communicating with the passages in thehollow member, and a second substantially airtight, telescoping conduitconnected between said discharge outlet and discharge opening, wherebythe hollow member may move relatively to the driving head during thesinking of the form.

EMANUE'L T. BEPLAT.

